Copycopter provides a nice interface that clients can use to edit the text in a Rails application. Learn how to deploy a Copycopter server using Heroku and integrate it in a Rails application through I18n.
(6 minutes)

Vagrant allows you to run your Rails application and all of its dependencies in a portable, sharable environment. Use for development, set it up as a staging server, or experiment with a production setup.
(11 minutes)

Guard watches files and runs a command after a file is modified. This allows you to automatically run tests in the background, restart your development server, reload the browser, and more.
(8 minutes)